The device disclosed herein relates generally to operating lever assemblies as are frequently used to select an operating mode of another device. More particularly, the device disclosed herein relates to detent mechanisms used in such operating levers to facilitate positive engagement in the desired position. Specifically, the device disclosed herein relates to such a mechanism having means to eliminate perching of the detent mechanism between desired positions.
Operating lever assemblies are frequently used to select operating modes of other devices and are often subject to vibration as work is performed. For obvious reasons it is desired that when the operator selects a desired position for an operating mode he or she is assured, despite vibrations, that the position chosen is obtained and will remain the same until another position is selected. Previously it has been known to utilize various types of detent mechanisms to accomplish and maintain the positive engagement of the lever in the selected position. One commonly used detent arrangement comprises a spring loaded ball or roller frictionally biased against a structure having receiving grooves, humps, or holes. Ordinarily, as the lever is moved from one position to another, the roller or ball will ride up the hump, compressing the spring until such movement allows the spring biased roller or ball to obtain the adjacent nested position. Under most circumstances selection of the desired position is accomplished in response to the directional movement of the lever and the frictional feedback from the detent. However, under certain circumstances the roller or ball will perch in a zone around the apex of the hump due to the fact that the tangential force component from the spring loaded ball or roller acting on the structure approaches the frictional force between the ball or roller and the structure, as the ball or roller nears the apex. This force balance condition is undesirable and can be unsafe inasmuch as the positive engagement of the detent in the desired position has not been accomplished. Accordingly, there is a clear need in the art for an improved detent mechanism which is effective to minimize the force balance condition and thereby eliminate the perching problem so as to allow the operating lever to be consistently positively engaged and maintained in the desired operating position.
In view of the foregoing, it is an object of the invention to provide an operating lever for selecting an operating mode of another device.
Another object of the invention is the provision of such an operating lever having a detent mechanism for positively engaging and maintaining a selected operating position.
A further object of the invention is to provide such an operating lever having means to minimize the force balance condition of the detent mechanism to eliminate perching.
An additional object of the invention is the provision of such an operating lever which provides a positive feel for operator feedback, including sound and force direction and is not vibration sensitive.
Still another object of the invention is to provide such a lever which is adaptable to a variety of applications.
The foregoing and other objects of the invention together with the advantages thereof over the known art which will become apparent from the detailed specification which follows are attained by a detent mechanism for an operating device assembly comprising: a detent housing; a first detent member having a plurality of adjacent detent notches therein with an apex between adjacent detent notches, the first detent member being rotatably disposed within the detent housing; means for biasing the first detent member against rotation; and, a second detent member frictionally engaging the first detent member, the second detent member being capable of movement relative to the first detent member and of selectively engaging the detent notches of the first detent member; whereby movement of the second detent member causes the first detent member to rotate in a first direction until the means for biasing exerts enough force on the first detent member to limit rotation of the first detent member in the first direction allowing the second detent member to move relative to the first detent member thereby unseating the second detent member from a detent notch and allowing the second detent member to move onto an apex between detent notches at which time the means for biasing exerts enough force on the first detent member to cause the first detent member to rotate in a second direction so as to cause the second detent member to engage an adjacent detent notch of the first detent member.
Other objects of the invention are attained by a detent mechanism for an operating lever assembly comprising: a spring; a detent plate having at least two legs extending there from and a plurality of adjacent detent notches therein with an apex between adjacent detent notches, the detent plate being disposed for limited rotational movement relative to the spring; and, a detent element biased against the detent plate, the detent element being capable of movement relative to the detent plate; whereby movement of the detent element causes limited rotational movement of the detent plate relative to the spring in a first direction bringing one of the legs into biased engagement with the spring until as the detent element approaches the apex between adjacent detent notches the bias force exerted upon the leg by the spring rotates the detent plate in an opposite direction causing the detent element to engage an adjacent detent notch.
Still other objects of the invention are attained by a detent mechanism for an operating lever assembly comprising: a main housing; a yoke mountably disposed within the main housing the yoke having a pair of standards and a bolster; a detent plate rotatably disposed within the yoke, the detent plate having at least two legs extending there from and a plurality of adjacent detent notches therein with an apex between the adjacent detent notches; a leaf spring supported by the standards of the yoke and interposed between the bolster of the yoke and the detent plate; and, a roller frictionally biased against the detent plate in the vicinity of the plurality of adjacent detent notches, the roller being capable of selective movement relative to the detent plate so as to enable the roller to frictionally engage individual detent notches; whereby movement of the roller causes the detent plate to rotate in a first direction within the yoke, bringing one of the legs of the detent plate into contact with the leaf spring such that continued rotation of the detent plate in the first direction causes the leaf spring to bias the detent plate in a second direction until as the roller approaches an apex between adjacent detent notches the leaf spring forces the detent plate in the second direction causing the roller to engage an adjacent detent notch.
Still further objects of the invention are attained by an operating lever assembly comprising: a main housing; a yoke mountably disposed within the main housing, the yoke having a pair of standards and a bolster; an actuator housing pivotally mounted to the yoke and movably disposed within the main housing; an operating lever operatively connected to the actuator housing; a detent plate rotatably mounted in the yoke, the detent plate having a pair of legs and a plurality of adjacent detent notches with an apex between each of the adjacent detent notches; a leaf spring having first and second ends, the leaf spring being interposed between the detent plate and the bolster of the yoke with the ends thereof being supported by the standards of the yoke; a roller pivotally mounted in the actuator housing, the roller being disposed for selective engagement of the detent notches of the detent plate; a compression spring disposed within the actuator housing, the compression spring frictionally biasing the roller against the detent plate; whereby manipulation of the lever causes the actuator housing to move and also causes the detent plate to begin to rotate in a first direction due to the frictional engagement of the roller as the roller is being unseated from a detent notch, bringing one of the legs of the detent plate into engagement with the leaf spring such that continued rotation of the detent plate causes the leaf spring to bias the detent plate in a second direction until as the roller approaches an apex between adjacent detent notches the leaf spring forces the detent plate in the second direction thereby causing the roller to nest in an adjacent detent notch.
Still other objects of the invention are attained by an operating lever assembly comprising: a main housing; a yoke mountably disposed within the main housing, the yoke having a pair of standards and a bolster; an actuator housing pivotally mounted to the yoke and movably disposed within the main housing; an operating lever operatively connected to the actuator housing; a detent plate mounted for limited rotational movement within the yoke, the detent plate having a pair of legs and a plurality of adjacent detent notches with an apex between each of the adjacent detent notches; a leaf spring having first and second ends, the leaf spring being interposed between the detent plate and the bolster of the yoke with the ends thereof being supported by the standards of the yoke; a roller pivotally mounted in the actuator housing, the roller being disposed for selective engagement of the detent notches of the detent plate; a compression spring disposed within the actuator housing, the compression spring frictionally biasing the roller against the detent plate; whereby manipulation of the lever causes the actuator housing to move and also causes the detent plate to begin to rotate in a first direction through a limited range due to the frictional engagement of the roller, bringing one of the legs of the detent plate into engagement with the leaf spring such that continued rotation of the detent plate causes the leaf spring to bias the detent plate in a second direction until as the roller is unseated from a detent notch and approaches an apex between adjacent detent notches the leaf spring forces the detent plate in the second direction thereby causing the roller to nest in an adjacent detent notch.
In general, a detent mechanism is provided for minimizing the force balance condition of an operating lever assembly. The detent mechanism has a detent housing with first and second detent members disposed therein. Means are provided for biasing the first detent member against rotation. The second detent member frictionally engages the first detent member while being capable of movement relative thereto. The second detent member is also disposed for selective engagement of detent notches provided on the first detent member, whereby movement of the second detent member with and relative to the first detent member causes the first detent member to rotate in a first direction until the means for biasing exerts enough force on the first detent member to cause the first detent member to rotate in a second direction causing the second detent member to engage an adjacent detent notch of the first detent member.
To acquaint persons skilled in the art most closely related to the device disclosed herein, embodiments illustrating the best mode now contemplated for putting the invention into practice are described herein by and with reference to, the annexed drawings that form a part of the specification. The exemplary embodiments are described in detail without attempting to show all of the various forms and modifications in which the invention might be embodied. As such, the embodiments shown and described herein are illustrative, and as will become apparent to those skilled in the art, can be modified in numerous ways within the spirit and scope of the inventionxe2x80x94the invention being measured by the appended claims and not by the details of the specification.